Cancer Incidence Rates in Eddy and Lea Counties

New Mexico, 1970-1994

Ovarian Cancer

Ovarian cancer is responsible for 6% of cancers in women (Crum 1994). Because ovarian cancers are not easily detected in early stages, they result in a disproportionate number of deaths. In 1993 in New Mexico, cancer of the ovary was the fifth most frequently diagnosed cancer among females, and the fourth most frequently diagnosed cancer among non-Hispanic white females (Figures 1 and 3).

During the period between 1986 and 1990, US women aged 65 years and over were diagnosed with this cancer almost six times more than women under 65 years (NCI 1993). Risk factors are not well understood for this cancer. Being infertile and having a family history of ovarian cancer have both been demonstrated to increase the risk of developing ovarian cancer. Other risk factors may involve diet and metabolism

Nationally, invasive ovarian cancer incidence rates have remained about the same over the last two decades, starting at 14.1 per 100,000 in 1973 and ending at 14.9 in 1990 (NCI 1993). While there was a slight peak from 1988 to 1990 (reaching 15.1 per 100,000 in 1989), the average incidence rate for the period between 1989 and 1990 (14.3 per 100,000), is consistent with other values between 1973 and 1990. Females 50 years old and over were diagnosed with this cancer about ten times more than women under 50 between 1973 and 1990. In New Mexico, incidence rates of invasive ovarian cancer were slightly lower than US rates. Statewide rates did not substantially change overall from 1970 to 1992, although they varied for intervening years, ranging from a low of approximately 12 per 100,000 around 1980, to a high of 15 in 1992 (Figure 37).

Spatial Variation

Spatial variation of incidence rates for ovarian cancer, for the period between 1970 and 1992, among females residing in New Mexico, Eddy County, and Lea County, is presented in Table 36.

Non-Hispanic Whites: During the period studied, the incidence rate for cancer of the ovary among non-Hispanic white females was 13.4 per 100,000 statewide, and ranged from a low of no cases in Guadalupe and Mora counties to a high of 26.2 in Harding County. Hispanic Whites: During the period studied, the incidence rate for cancer of the ovary among Hispanic white females was 10.9 per 100,000 statewide, and ranged from a low of no cases in De Baca, Harding, Los Alamos, and Union counties to a high of 24.6 in Torrance County. The incidence rate for cancer of the ovary among Hispanic white females in Eddy County was 11.6 per 100,000 (the tenth highest county rate among Hispanic white females in New Mexico).

Temporal Variation

Temporal variation of incidence rates for ovarian cancer, for the period between 1970 and 1994, among females residing in Eddy County and Lea County is presented in Figures 37 and 38.

Females: Statewide, ovarian cancer incidence rates did not change substantially during the period studied, varying between 12 and 14 per 100,000. In Eddy and Lea counties, ovarian cancer incidence rates varied widely, making trends difficult to describe; however, rates appear to be comparable with statewide rates.

By Ethnicity: Statewide, ovarian cancer incidence rates during the period studied did not change substantially among non-Hispanic whites, although they decreased slightly among Hispanic whites, from approximately 13 per 100,000 in 1971 to 10 in 1993. In Eddy and Lea counties, rates for Hispanic whites were often higher than rates for non-Hispanic whites. In Eddy County, ovarian cancer incidence rates during the study period decreased among non-Hispanic whites, from approximately 15 per 100,000 in 1971 to 12 in 1993, and among Hispanic whites, from approximately 28 per 100,000 in 1971 to 18 in 1993. In Lea County, ovarian cancer incidence rates for non-Hispanic whites decreased over the study period, from approximately 15 per 100,000 in 1971 to 6 in 1993. Rates for Hispanic whites varied during the study period, with no cases of ovarian cancer among Hispanic whites reported for many of the years studied.